

© Copyright 1995 thru 2008 - The Mustang Works™. All Rights Reserved.
MustangWorks.com is designed and hosted by Aero3 Media.
MustangWorks.com is designed and hosted by Aero3 Media.
![]() |
#1 |
Registered Member
Join Date: Jan 2001
Location: Salt Lake City
Posts: 117
|
![]() I'm still trying to pick a TB for my combo. I had pretty much settled on a 65 but then I ran across the MAC 70mm that is cheap and has a plate.
I've heard that 70 & up can hurt low end. I autocross alot and don't want to lose any of that grunt coming out of the corners. Since I will have much more hp I'm thinking that I wouldn't notice it too much. I also think I'm on the edge of moving up from a 65 anyway. Anybody have an opinion on the MAC, 70mm size, or what your car did when you changed? Thanks, Dan
__________________
Spec Service (UHP), BFG G-Force KDW's, Turbo Coupe 3.55 rear w/disks, 73mm calipers, Stg 1 Twisted Wedges, TFS Street Intake, 70mm TB, E cam, Crane 1.7's, Aeromotive FPR, BBK 1 5/8 shorties, elec fan, FMS Al Radiator, Moroso Wires, Kenne Bell Ramair, March pulleys, Race Magnums, 190 lph Walbro, FMS Al Dshaft, D/S loop, MM 4point rollbar, FMS C spngs, strut tower brace, Tokico Illuminas, Prothane bushings, MM Lwr Conrol Arms, KB welded subs, Cervini Mach 1 hood/valence/side skirts/wing/airdam. |
![]() |
![]() |
![]() |
#2 |
News Editor
Join Date: Apr 1999
Location: Concord, CA
Posts: 2,101
|
![]() Technically a 65mm TB can hold up to 400hp, but a 70mm would not be too bad a good intake/cam/heads combo.
__________________
Scott Halihan, News Editor The MustangWorks Magazine 1994 Supercharged Mustang Cobra Rebel Racing. Home of Bay Area Mustangs |
![]() |
![]() |
![]() |
#3 |
Mustangs
Join Date: Jul 2000
Posts: 1,938
|
![]() My GT with only mild mods has a 70mm Edelbrock Throttle body and EGR plate and the stock intake was ported to match. From what i've noticed it's really not bad, but then again with the 3.55 gears it's not often i'm below 2,000rpm. Power really picks up around 2500 and i suppose it helps that my car has the stock MAF sensor to increase velocity (stiffle air flow), which will soon be removed for a larger unit. But I haven't noticed any negative effects like low rpm sputtering or anything else. Unlike a carbureted vehicle, you don't need a strong vacuum signal through the throttle body to help pull fuel... a nice man in a silver box does that for you (the ECU).
__________________
2005 Suzuki Hayabusa GSX1300-R 1980 Ford Thunderbird - 255 V8 ported heads, 5.0L ported stock headers, O.R. H-pipe and Flowmaster 2-chambers, dual roller timing chain hi-po Mack Truck hood emblem ![]() 1985 Mustang GT 5.0L T5, F-303, GT40p, headers, off-road h, flowmasters, MSD stuff, etc. Sold 02/06/04 ![]() 1989 Mustang GT ET: 13.304@102.29 mph (5-24-03) Sold - 1998 Mustang Cobra coupe, 1/4 mile - street tires: 13.843@103.41 (bone stock) |
![]() |
![]() |
![]() |
#4 |
or '331 LX Eric'
Join Date: Jan 1999
Location: Columbus, Ohio
Posts: 2,142
|
![]() The 70 mm will probably be just fine. I doubt that you would really lose that much low-end torque. Plus, when autocrossing, how often are you under say 2500-3000 rpms? Probably not that much, right?
Sounds like you're putting together a a solid combo. Keep us posted on the install and results. Good luck, E
__________________
1991 5.0 LX Coupe - 40,750 miles 331 cu. in. / Tremec 3550 / BFG Drag Radials 12.22 @ 114.31 mph - w/1.89 60' |
![]() |
![]() |
![]() |
#5 |
Registered Member
Join Date: Nov 2001
Location: Sunny, Hot, Sebring, Florida
Posts: 725
|
![]() Remember, when naturally aspirated, more air is better, A 70mm will not lose you torque, what size mas do you have, that is a consideration as well, i work for Skip Barber Racing School here in Sebring, Florida. Want some insider rracer tips from Juan Montoya, just a little lunch at Wendy's to pick his brain back when he dominated the Pro Series.
i am currently an instructor, and would love to instruct you on-line, there are some things you can learn on paper as well as the track. i'm bored.
__________________
Remember...2nd place is 1st place for losers! |
![]() |
![]() |
![]() |
#6 |
Registered Member
Join Date: Jan 2001
Location: Salt Lake City
Posts: 117
|
![]() Stock MAF
When I can afford it I will go with 24lb injectors and a calibrated 73mm. Who knows, if this baby runs good enough I may forgo the injectors/MAF and concentrate on paying off this growing pile of engine upgrade debt that the wife doesn't know about yet....! Dan
__________________
Spec Service (UHP), BFG G-Force KDW's, Turbo Coupe 3.55 rear w/disks, 73mm calipers, Stg 1 Twisted Wedges, TFS Street Intake, 70mm TB, E cam, Crane 1.7's, Aeromotive FPR, BBK 1 5/8 shorties, elec fan, FMS Al Radiator, Moroso Wires, Kenne Bell Ramair, March pulleys, Race Magnums, 190 lph Walbro, FMS Al Dshaft, D/S loop, MM 4point rollbar, FMS C spngs, strut tower brace, Tokico Illuminas, Prothane bushings, MM Lwr Conrol Arms, KB welded subs, Cervini Mach 1 hood/valence/side skirts/wing/airdam. |
![]() |
![]() |
![]() |
#7 |
Registered Member
Join Date: Nov 2001
Location: Sunny, Hot, Sebring, Florida
Posts: 725
|
![]() sounds like 24's will be plenty for you, whew!, GOOD LUCK.
__________________
Remember...2nd place is 1st place for losers! |
![]() |
![]() |
![]() |
#8 |
Registered Member
Join Date: May 1999
Location: Georgia
Posts: 3,866
|
![]() stick with the 65mm. its all you need and throttle response will be much better, which you will want for autocrossing.
Ive had both, a 70mm BBK and a 65mm Ford motorsport, and I speak from personal experience. the difference in power between a 65 and 70mm on a combo like yours is non-existent, but again, throttle response is much better |
![]() |
![]() |
![]() |
#9 |
Backyard Mechanic/Chemist
Join Date: Feb 2001
Location: Acton MA USA
Posts: 435
|
![]() I had posted a similar question a while back and EVERYONE said go for a 65 mm. Sounds like he still has a stock TB and is wondering if he should get a 65 or 70MM unit.
Mac only sells a 70mm unit, they claim it makes somewhat more power than a 65 mm with no real torque loss therefore they felt the 65 mm was not necessary. Of course that is their opinion, many other mfr's make 65 mm units. I was pretty sold on a 65 for my car till now, this is interesting. I have a set of cobra 24# injectors, and need new headers and h pipe. Still have original fuel pump, TB, MAF etc So.. I was figuring on going long tube 1 5/8 headers with cat H pipe, 155 LPH pump Adjustable FPR, the 24# injectors, a 76 MM C&L MAF calib for 24# with the alum connector pipe, and a new TB. Now I am thinking a 70MM unit again ARRGH Also have a pulley set and a 130 amp alt to install too, too dam cold for now!
__________________
2001 Crown Vic Maurader Airbox/MAF, DR chip Edel IAS shocks Single exhaust :wtf: 93 P-71 Vic interceptor Backup car now 90 5.0 LX Notch SOLD 74 Chevy Laguna type S-3 454 under construction Currently apart undergoing bodywork. |
![]() |
![]() |
![]() |
#10 |
Registered Member
Join Date: Jan 2001
Location: Salt Lake City
Posts: 117
|
![]() I searched the past posts and came up with the same 65mm majority opinion.
Then I ran into the MAC thing. You can get TB & Plate for $170-180 but will pay $225 & up for the 65mm by the time you pay extra for the Plate too. Seems like the polished surface also appeals to people. So the size vs performance traits is my last issue. My understanding is that after you do heads, intake, and exhaust the stock TB & MAF are next culprits. Appreciate the advice so far.... Dan
__________________
Spec Service (UHP), BFG G-Force KDW's, Turbo Coupe 3.55 rear w/disks, 73mm calipers, Stg 1 Twisted Wedges, TFS Street Intake, 70mm TB, E cam, Crane 1.7's, Aeromotive FPR, BBK 1 5/8 shorties, elec fan, FMS Al Radiator, Moroso Wires, Kenne Bell Ramair, March pulleys, Race Magnums, 190 lph Walbro, FMS Al Dshaft, D/S loop, MM 4point rollbar, FMS C spngs, strut tower brace, Tokico Illuminas, Prothane bushings, MM Lwr Conrol Arms, KB welded subs, Cervini Mach 1 hood/valence/side skirts/wing/airdam. |
![]() |
![]() |
![]() |
#11 |
Registered Member
Join Date: Apr 2001
Location: Bowling Green, OH
Posts: 270
|
![]() Take this for what it's worth....
When MM&FF was putting together their stone pony project car, they tested a 65mm (ford racing) and 70mm TB (edelbrock/bbk) on the dyno. The mods on the car were edelbock performer Heads/cam/intake plus all the bolt-ons. I think the car was making 270-280 rwhp at the time. Anyways, they claim that the dyno runs between the 2 TBs were identical, and you could lay one graph on top of the other and not notice a single difference. IMO, go with the 65mm.
__________________
1989 lx notch 89,000 miles 5-speed, bolt-ons, 3.73, TFS TWs, TFS Track Heat, TFS Stage 1 cam |
![]() |
![]() |
![]() |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
raced a Supra Twin Turbo | Stang35th | Stang Stories | 63 | 08-23-2003 12:36 AM |
Torque strap. Yes or no | Dark_5.0 | Windsor Power | 3 | 06-05-2003 07:00 AM |
T-5 Torque Rating | sleeperstang | Classic Mustangs | 5 | 07-05-2002 10:54 PM |
T-5 Torque Rating | sleeperstang | Windsor Power | 1 | 06-27-2002 08:18 PM |
what kind of torque converter? | Reipen | Windsor Power | 1 | 04-29-2002 02:45 PM |